Latrodectus geometricus
(Brown Widow Spider)

Featured spider picture The spider species Latrodectus geometricus, commonly known as Brown Widow Spider, belongs to the genus Latrodectus, in the family Theridiidae. Latrodectus geometricus spiders have been sighted 43 times by contributing members. Based on collected data, the geographic range for Latrodectus geometricus includes 8 countries and 3 states in the United States. Latrodectus geometricus is most often sighted outdoors, and during the month of March.

Taxonomic Hierarchy

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Suborder: Araneomorphae
  • Family: Theridiidae
  • Genus: Latrodectus
  • Species: Latrodectus geometricus

Common Name (AASMore information icon)

Brown Widow

Other Common Names

Gray Widow, Widow Spider, Brown Button Spider, Geometric Button Spider, Hourglass Spider, Cobweb Spider, Cob Web Spider, Comb-footed Spider, Tangle-web Spider, Gumfoot-web Spider

Author

Carl Ludwig Koch, 1841

Primary Colors


Sightings Overview

There have been 43 confirmed sightings of Latrodectus geometricus (Brown Widow Spider), with the most recent sighting submitted on April 9, 2018 by Spider ID member kbarnett. The detailed statistics below may not utilize the complete dataset of 43 sightings because of certain Latrodectus geometricus sightings reporting incomplete data.

  • Web: 47% of the time, Latrodectus geometricus spiders are sighted in a spider web (Sample size: 17)
  • Sex: 19 female and 4 male.
  • Environment: Latrodectus geometricus has been sighted 11 times outdoors, and 7 times indoors.
  • Outdoors: Man-made structure (9). Low foliage (2).

Location and Range

Latrodectus geometricus (Brown Widow Spider) has been sighted in the following countries: Argentina, Bahrain, Brazil, Curacao, India, Israel, South Africa, United States.

Latrodectus geometricus has also been sighted in the following states: California, Florida, Georgia.

Seasonality

Latrodectus geometricus has been primarily sighted during the month of March.

  • January: 7
  • February: 3
  • March: 8
  • April: 3
  • May: 2
  • June: 4
  • July: 4
  • August:
  • September:
  • October:
  • November:
  • December: 1

Additional Remarks

  • Not the only “widow spider” in North America; there are also four other species of Latrodectus.
  • This spider may be common in yards and gardens, sometimes building its web in more exposed situations than other species of Latrodectus.
  • Egg sacs are brown or beige spherical tufted/spiky objects that may be the best clues in identifying this species when the spider itself is not present (no other species of widow creates spiky egg sacs). Each one is ~10 millimeters in diameter and contains anywhere from 80-150 eggs; the species is very prolific, with females producing up to 20 sacs in their lifetime.
  • The venom of this species is potentially dangerous to humans, but the spider itself is timid and non-aggressive. Like other species of Latrodectus, its venom is neurotoxic, and while it’s likely to be just as potent as that of other widow spiders, it’s thought that they inject far less venom and bites usually only result in localized pain and swelling.
  • The spider can be mistaken for the “Common House Spider,” Parasteatoda tepidariorum. Check for a red or orange hourglass marking on the underside of the abdomen, which is present on Latrodectus but not on Parasteatoda. The eye arrangements and egg sacs are also very different between the two types of spider.

Featured Pictures

Picture of Latrodectus geometricus (Brown Widow Spider) - Female - Ventral,Webs Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Female - Lateral,Webs Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Ventral,Webs Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Ventral,Webs Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Ventral,Webs Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Ventral,Webs Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Lateral,Prey Enlarge Picture
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Picture of Latrodectus geometricus (Brown Widow Spider) - Lateral Enlarge Picture
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